Ancient Chinese mythology explains the tilt of the heavens as a structural repair job

The 'Huainanzi', compiled around 139 BCE, records that the goddess Nüwa saved the world after the water god Gonggong shattered Mount Buzhou, one of the pillars supporting the sky. This catastrophic event caused the heavens to tilt toward the northwest and the earth to sink in the southeast, explaining why Chinese rivers flow toward the ocean. Nüwa mended the sky by smelting five-colored stones and using the legs of a giant tortoise to replace the broken supports.